This lecture involves a quarrel between Galileo Galilei, newly established as early modern Europe’s premier astronomer, and an aristocratic student at a Jesuit college. At stake here is the staying power of this particular struggle, which first emerged around 1613 and then resurfaced nearly twenty years later in Galileo’s celebrated discussion of the imperceptibility of common motion. Though this conflict began with elaborate displays of indifference, it soon depended upon comic manipulation of the opponent’s arguments, a fable concerning a shipboard artist, and an extraordinary series of odd, distracting woodcuts.